1. Technical Field
The present invention relates generally to starting mechanisms of vehicles and, more particularly, to control of the starter motor of a vehicle after the vehicle is running.
2. Discussion
Typically, a vehicle engine has a starter motor, which is activated through a relay, when the ignition switch is engaged in the "start" position. Generally, switches enable the deliverance of electrical power to energize the starter relay, if the vehicle ignition switch is turned "on". Upon the occurrence of such an event, the starter relay will be responsible for transmitting power to the starter solenoid, which engages the starter pinion to the powertrain ring gear and allows current to flow to the starter motor. The starter motor system provides transitional and rotational movement to a starter pinion gear, which then meshingly engages a ring gear of an engine crankshaft.
Current starting systems of vehicles do not fully engage the starter motor after start-up. Hence, the starter motor can engage the pinion gear to the ring gear of the engine even after the vehicle is running. Recent advances in engine vibration reduction, knock control, and exhaust systems have reduced the amount of noise vehicles make when they are running. As a result, inadvertent re-starts are often caused by vehicle operators, since they are unable to ascertain whether the engine is running. Upon such an occurrence, clashing ("milling") of the pinion and ring gears may result. Therefore, wear may be imparted on the gears. In addition, such engagement may result in unnecessary noise to the vehicle operator.
Furthermore, most manually activated cranking systems have an over-running clutch in the starter motor to disengage or unload the pinion gear from the ring gear. This type of clutch system has a disadvantage that the pinion gear continues to be rotated at high speed by the engine-driven ring gear as long as the operator continues to run the starter motor by keeping the ignition switch in the "start" position. As a result, such a system will not be of use when a vehicle operator inadvertently re-starts the vehicle with prolonged engagement of the clutch since the pinion and ring gears will not disengage. Furthermore, prolonged engagement between the pinion gear and ring gear when the ignition switch is in the "start" position and the engine has failed to start, may also result in abrasive wear on the gears. Additionally, if the engine starts and runs, the starter motor armature could "overspin" and become destroyed. Finally, such a clutch mechanism adds to the overall weight, cost, and size of the transmission system.